In aircraft cabins in which the seats can be converted into beds, the arrangement of the said seats must take account of several criteria: it is in fact necessary to provide the passengers not only with a high level of comfort but also optimum safety conditions, whilst providing a sufficient number of seats per cabin to meet the economical requirements related to this type of transport.
Arrangements of seats are already known which can be converted into beds, for aircraft cabins, in which the seats are disposed in several longitudinal rows. These arrangements provide a central group and two lateral groups of rows situated in each side of a central group, the central group being separated from the two lateral groups respectively by a gangway. However, in this type of arrangement, the passengers which are situated at a distance from a gangway are obliged, in order to gain access to the said gangway, to step over their neighbour if the latter has placed his seat in the bed position. This type of arrangement is therefore not very satisfactory in terms of comfort, but also in terms of safety, if for example the passengers have to go quickly to the emergency exits.